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  • 2014 Volume 69 Issue 5
    Published: 20 May 2014
      
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  • Hydro-Informatic Modeling System：Aiming at water cycle in land surface material and energy exchange processes
    LIU Changming, WANG Zhonggen, YANG Shengtian, SANG Yanfang, LIU Xiaomang, LI Jun
    2014, 69(5): 579-587. https://doi.org/10.11821/dlxb201405001
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    Following the theory of geography science, especially the theory about land surface system, we investigated the development tendency of hydrological cycle study. On the whole, the study object of hydrology develops from signal-factor process to multi-factor processes in a watershed, and further to the integration of water systems by considering multivariables, multi-processes and multi-scales. Therefore, it is important to develop an integrated hydrological modeling system. We proposed the Hydro-Informatic Modeling System (HIMS), which aims at water cycle in the land surface material and energy exchange processes. The HIMS system takes the water cycle as a complete system, and conducts integrally hydrological modeling. The development processes, main structure and special functions of the HIMS system were overviewed in detail. The developments of HIMS system have obvious three stages. It includes the platform of multi-source information integration, the system of multi-factor quantitatively remote sensing inversion, the integrated system of multiwater processes, and the multi-scale distributed water systems by considering customization. The practicality and progressiveness of the HIMS system have been verified in various applications at home and abroad. Finally, it is pointed out that interdisciplinary study in combination with information technology is one of major tendencies for HIMS development. The basic theories should be concentrated on hydrological cycle, and the simulation functions would be further extended to improve the development of the HIMS system. In the future, the HIMS system can be applicable for the needs of integral water system study, and can be an effective tool for researching water-related issues under the impacts of environmental change.
  • From experimental hydrology to hydrological system modeling：Some understandings about the hydrological science studies by Academician Liu Changming
    ZHOU Chenghu, LIU Suxia, YU Jingjie, SONG Xianfang
    2014, 69(5): 588-594. https://doi.org/10.11821/dlxb201405002
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    As an internationally renowned expert on hydrology and water resources research, Academician Liu Changming has long been endeavouring to promote the studies on hydrological circle, water environment, water ecology, water resources and water-related hazards. He has sought to integrate the hydrological studies from geophysics, engineering and geography. He also argued that hydrological circle research must be based on the micro and macro-systems. He proposed a theoretical model of five-water transfer, developed a new distributed hydro-informatic modeling systems. His theory and methods in the field of hydrological science have been widely applied in the production practices such as the watersaving agriculture development in the North China Plain, environmental effects evaluation of South-to-North Water Transfer Project, and combating against the Yellow River dry-up. In this paper, the authors tried to understand the systematic hydrological theories and innovations from his studies and research activities over the last 50 years or more in terms of experimental hydrology, prediction in ungauged basins and hydrological models.
  • Influencing factors and classifications of arc-shaped coasts in South China
    LI Zhiqiang, LI Weiquan, CHEN Zishen, ZHU Yamin
    2014, 69(5): 595-606. https://doi.org/10.11821/dlxb201405003
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    Using the principal component analysis, hierarchical cluster analysis and nonmetric multidimensional scaling analysis, 10 factors affecting coastal plain shape and hydrodynamic of 47 arc-shaped coasts were analyzed, aiming to study the influencing factors and classification spectrum of arc-shaped coast in South China. The results show that: (1) the plane forms of South China's arc-shaped coasts were mainly controlled by geological structure conditions, hydrodynamic conditions (wave and tidal range) and sediment supply. (2) The arc-shaped coasts in South China can be divided into four categories, and each category has several small types. The first category is meso-and macrotidal coast; the second is strong wave coast; the third is geological structure controlled large arc-shaped coast; the fourth, consisting of Yangpu Bay and Puqian Bay, is a unique type of arc-shaped coast. (3) Nonmetric multidimensional scaling analysis reveals the effects of morphodynamic factors on the coastal shape and the types, which shows that the categories are objective. These conclusions will be helpful to the arc-shaped coasts processes research and engineering constructions in South China.
  • Vulnerability assessment of coastal erosion along the Abandoned Yellow River Delta of northern Jiangsu, China
    LIU Xiaoxi, CHEN Shenliang, JIANG Chao, HU Jin, ZHANG Lin
    2014, 69(5): 607-618. https://doi.org/10.11821/dlxb201405004
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    The Abandoned Yellow River Delta of northern Jiangsu faces serious erosion hazard due to global climate change, sea-level rise, human activities and shortage of sediments. In this present work, coastal erosion hazard and vulnerability level along the Abandoned Yellow River Delta have been assessed with the aid of RS and GIS. The coastal vulnerability index (CVI) is used to map the relative vulnerability in the study area. Shoreline change rate, depth contours change rate, coastal slope, subaqueous slope, sedimentary dynamic environment, suspended sediment concentration, mean high tidal height, utilization of coastal types and coastal development suitability are used as the evaluation indexes to assess the coastal erosion hazard and vulnerability level. Analytic hierarchy process (AHP) is used to calculate the weights of each evaluation index. The results show that the Abandoned Yellow River Delta presents a high coastal erosion vulnerability level. The vulnerability level indicates that over 50% of the study area presents a high and very high vulnerable level, and over 75% of coastal area presents above the moderate vulnerable level. The coastal erosion vulnerability map prepared from this study can provide reference for the coastal zone protection, disaster prevention and mitigation, proper planning and management of this coastal region.
  • Phases and periodic changes of water discharge and sediment load from the Yellow River to the Bohai Sea during 1950-2011
    REN Huiru, LI Guosheng, CUI Linlin, HE Lei
    2014, 69(5): 619-631. https://doi.org/10.11821/dlxb201405005
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    On the basis of situ data observed at Lijin station from 1950 to 2011, the regional differences and abrupt changes of water discharge and sediment load are divided into different phases using the methods of Mann-Kendall test and order clustering. The abrupt change of water discharge and sediment load existed at Lijin station in 1985, and discharge and sediment decreased insignificantly from 1985 to 2011. The characteristics of the periodicities of water discharge and sediment load from the Yellow River estuary are studied by using power-spectrum, cross-spectrum and wavelet analysis. The periodic oscillations of water discharge and sediment load from the Yellow River are found at inter-annual scale and decadal scale. The significant correlation coefficients between two datasets occur at the scales of 2.86a, 4.44a and 13.33a. The phase characteristics of water discharge and sediment load are related to the precipitation and human activities; after the 1980s the decreases are mainly induced by human activities, especially due to the use of the reservoirs, water diversion and engineering projects related with soil and water conservation. Moreover, the inter-annual and decadal fluctuation of water discharge and sediment load from the Yellow River are caused directly by the oscillation of the precipitation at the drainage basin, and the rudimentary mechanism of multi-scale fluctuations are due to the northwest Pacific subtropical high, whose location oscillates in inter-annual and decadal periods, as well as sun spot and precipitation,. The decadal scale periodic oscillation of water discharge and sediment load from the Yellow River cause abrupt changes. The main reason for the stepwise step of phase is related with human activities.
  • Characteristics and origins of drought disasters in Southwest China in nearly 60 years
    HAN Lanying, ZHANG Qiang, YAOYubi, LI Yiping, JIA Jianying, WANG Jing
    2014, 69(5): 632-639. https://doi.org/10.11821/dlxb201405006
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    Drought is a meteorological disaster that causes huge losses to agricultural yields every year. This paper analyzed drought trends based on statistical disaster data, which included drought-induced areas, drought-affected areas, and lost harvests under the effects of global warming. The results showed that droughts are becoming more critical and frequent in China. The agricultural effects of drought for drought-induced areas, drought-affected areas, lost harvest areas and comprehensive loss rate increased in the last 60 years in each province of Southwest China. It is important to examine the spatial and temporal changes in the agricultural effects of drought in guiding disaster mitigation work. This paper analyzed the drought conditions in large farming areas of Southwest China, which were frequently hit by serious droughts. Total drought area ranked first in Sichuan Province, second in Guizhou Province, and third in Yunnan Province. The average annual comprehensive loss rate accounted for 3.9% in Southwest China, and increased in recent years. Drought tolerance of all provinces is related to regional climate change effects, such as temperature, precipitation, moisture, and vegetation coverage.
  • Changes in precipitation extremes in South China during 1961-2011
    REN Zhengguo, ZHANG Mingjun, WANG Shengjie, ZHU Xiaofan, DONG Lei, QIANG Fang
    2014, 69(5): 640-649. https://doi.org/10.11821/dlxb201405007
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    Based on the daily precipitation from a 0.5° × 0.5° gridded dataset and meteorological stations during 1961-2011 released by National Meteorological Information Center, this paper evaluates the reliability of this gridded precipitation dataset in South China. Five precipitation indices recommended by the World Meteorological Organization (WMO) were selected to investigate the changes in precipitation extremes in South China. The results indicate that the limited bias was observed between gridded data interpolated to given stations and the corresponding observed data, and that 50.64% of the stations had bias between -10% and 0. Generally, the correlation coefficients between gridded data and observed data are above 0.80 in most parts of the region. The average of precipitation indices shows a significant spatial difference with drier northwest section and wetter southeast section. The trend magnitudes of maximum 5-day precipitation (RX5day), very wet day precipitation (R95), very heavy precipitation days (R20mm) and simple daily intensity index (SDII) were 0.17 mm·a-1, 1.14 mm·a-1, 0.02 d·a-1 and 0.01 mm·d·a-1, respectively, while consecutive wet days (CWD) decreased by -0.05 d·a-1 during 1961-2011. There is spatial disparity in trend magnitudes of precipitation indices, and approximate 60.85%, 75.32% and 75.74% of the grid boxes showed increasing trends for RX5day, SDII and R95, respectively. There were high correlations between precipitation indices and total precipitation, which was statistically significant at the 0.01 level.
  • The spatio-temporal change of active accumulated temperature ≥ 10℃ in Southern China from 1960 to 2011
    DAI Shengpei, LI Hailiang, LUO Hongxia, ZHAO Yifei
    2014, 69(5): 650-660. https://doi.org/10.11821/dlxb201405008
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    The spatial and temporal variation of active accumulated temperature ≥10℃(AAT10) was analyzed by using the linear trend line method, cumulative anomaly method and multiple linear regression interpolation method based on the daily meteorological observation data from 104 meteorological stations in Southern China and surrounding 39 meteorological stations during 1960-2011. The result shows that: (1) From time scale point of view, the climatic trend of AAT10 increased with an average of 7.54oC/10a in Southern China since 1960. The area of AAT10<6000℃decreased from 1960 to 2011, and the area of 6000℃<8000℃ decreased from 1960 to 1979 and increased from 1980 to 2011, and the area of AAT10>8000℃ increased from 1960 to 2011. (2) From spatial scale point of view, the AAT10 in Southern China was reduced with increasing latitude and increasing altitude. The area of 5000℃<8000℃ occupied 70% of the study area, followed by that of 4000℃<5000℃; and the areas of AAT10<4000℃ and AAT10>8000℃ were the least. The climate trend rate at 99% of the meteorological stations of the AAT10 was greater than zero, suggesting that the AAT10 increased significantly in the central Yunnan province, southern Guangdong province and Hainan Island. (3) Comparison of period I (1960-1989) and period II (1980-2011) with the change of climatic zones indicates that the North Tropical Zone, South Subtropical Zone and Central Subtropical Zone gradually expanded, and North Subtropical Zone and Temperate Zone showed a decreasing trend. The change of climatic zones expanded to high altitude and latitude. (4) The increase of AAT10 is conducive to the production of tropical crops planted, which will increase the planting area suitable for tropical crops, and expand the planting boundaries to high latitude and high altitude.
  • Change features of precipitation events in Shandong Province from 1961 to 2010
    DONG Xuguang, GU Weizong, MENG Xiangxin, LIU Huanbin
    2014, 69(5): 661-671. https://doi.org/10.11821/dlxb201405009
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    Based on daily precipitation data of 121 weather stations in Shandong Province from 1961 to 2010, this paper analyzed the features of precipitation days and intensity including climate characteristics, trends, contribution rate, variation field, abrupt change and periodicity. The results indicated that with a significant drop of days, both annual precipitation days and intensity showed an obvious decadal oscillation. Annual precipitation days and intensity presented evident zonal distribution and gradually decreased from southeast to northwest. Precipitation intensity of heavy rainfall in various places were more uniform, meanwhile days and intensity of extreme rainfall were more and higher in mountain area of southern Shandong than in the northern part. There were 116 stations showing a decreasing trend of annual rainfall days and 80 stations presenting an increase of intensity. Furthermore, days of heavy rainfall decreased and intensity of extreme rainfall had become higher apparently. Heavy and extreme rainfall days on a small proportion, however contributed significantly to the annual precipitation. Since the 21st century, the days and precipitation percentage of heavy rainfall and extreme rainfall had an increasing trend. The average rainfall days and variation coefficient changed greatly in the mid-1960s, 1990s and early 21st century. Variation coefficient of different precipitation events showed similar decadal changes, while that of the same precipitation event in different decadal differentiated evidently. The average rainfall days and heavy rainfall intensity mutated in 1977 and 2005 respectively. Heavy rainfall and extreme rainfall days had variation major periods of 5 years and 11 years respectively, while precipitation intensity of different grades had periods of 13 years and 21 years respectively.
  • Influence of climate warming in winter on the winter wheat cultivable area in Shanxi Province
    QIAN Jinxia, LI Na, HAN Pu
    2014, 69(5): 672-680. https://doi.org/10.11821/dlxb201405010
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    Based on the daily mean temperature data of 70 meteorological stations in Shanxi Province from 1970 to 2012, the negative accumulated temperature in winter, average monthly temperature in January and extreme minimum temperature were computed and their changing trends were analyzed in this paper using linear trend estimation method, and their abrupt change points were observed by means of accumulated variance method and contours of the negative accumulated temperature in winter, average monthly temperature in January and extreme minimum temperature were compared respectively after being divided into two groups according to the abrupt change points. The results showed that the negative accumulated temperature in winter showed a remarkable decrease, and the average monthly temperature in January and extreme minimum temperature did not increase significantly. Changes were found between the two groups, the negative accumulated temperature decreased by 103.4℃, and the average monthly temperature in January and extreme minimum temperature rose by 0.7℃and 0.9℃, respectively. The negative accumulated temperature and extreme minimum temperature played a key role, which are the thresholds that the winter wheat Province could be planted or not. Under climatic warming, the winter wheat cultivable area and the reliable planting area expanded by 2.9×106 hm2 (increased by 52%) and 2.3×106 hm2 (rose by 79%), respectively.
  • Variations of the alpine precipitation during 1960-2006 recorded in Laohugou ice core in western Qilian Mountains, China
    QIN Xiang, CUI Xiaoqing, DU Wentao, REN Jiawen, CHEN Jizu
    2014, 69(5): 681-689. https://doi.org/10.11821/dlxb201405011
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    The accumulation record of ice core is one of the most reliable indicators for reconstructing precipitation changes in high mountains. A 20.12 m ice core was drilled in 2006 from the accumulation zone of Laohugou Glacier No.12 in northeast Tibetan Plateau, China. We obtained the precipitation from the ice core net accumulation during the past 50 years, and found out the relationship between ice core record and other data from surrounding sites. Results showed that during 1960-2006, the precipitation in the high mountains firstly increased and then decreased. In 1960-2006, precipitation showed a significant increasing trend, while, from 1980 to 2006 it showed a decreasing trend. Reconstruction of the precipitation changes in the glacier was consistent with the measured data from the weather station in low mountain of Subei, and the correlation coefficient was 0.619 (P < 0.001); however, the magnitude in the high mountains was three times higher than that of the low mountain. The precipitation of Laohugou Glacier No.12 corresponded well to the amount of accumulation of the Dunde ice cores in the same period, tree-ring reconstruction of precipitation, the measured data of multiple meteorological stations in the northeastern Tibetan Plateau, and the changes of adjacent PDSI drought index. Precipitation changes of Laohugou Glacier and the northeastern Tibetan Plateau had significantly positive correlation with ENSO, which reflected the regional alpine precipitation change was likely to be influenced by ENSO.
  • Spatial and temporal distribution of frost days over Tibet from 1981 to 2010
    Labaciren, Suolangjiacuo, Baima
    2014, 69(5): 690-696. https://doi.org/10.11821/dlxb201405012
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    The annual and decadal variations, anomalous and abrupt change of the frost days are analyzed in this paper, using the daily minimum temperature of 38 stations over Tibet from 1981 to 2010 and modern statistical diagnosis methods, such as linear trend analysis, accumulative anomaly, signal noise ratio and rescaled range analysis (R/S analysis). The results showed that, (1) in recent 30 years, the frost days decreased with a rate of (3.3-14.6) d/ 10a (P<0.01, at 37 stations), and the damping of frost days increased with increasing altitude. (2) In terms of decadal variations, the frost days presented a negative anomaly in the 1980s and a positive anomaly in the 2000s, the positive anomaly range of frost days was larger than the negative anomaly in the 1990s. (3) It was found with abrupt change test that frost days at eight stations had abrupt change, which occurred in the 1990s with the year 1997 having the largest number. (4) The results of R/S analysis showed that changes of frost days had the persistence with a Hurst index larger than 0.5 at most of the stations, and indicated that it will assume a continuous decrease in future and the decreasing rate will became larger. (5) In addition, it was found that the frequency of anomalous (more than normal) frost days was 0 to 3 times and occurred mainly in the 1980s, while the anomalous (less than normal) frost days occurred in the 2000s with a frequency of 0 to 4 times. There is little correlation between altitude (or latitude, longitude) and anomalous more frost days frequency, while altitude has negative correlation with anomalous less frost days frequency.